part of embryonic/larval dorsal pouch dorsal fold FBbt:00001860 fly_anatomy.ontology Epidermal structure of the embryo head which is part of the dorsal pouch. It is formed during germ band elongation shortening, at the time when the dorsal ridge moves dorsally to reach the midline and fuse with its complement on the other side. The fold progressively moves over the clypeolabrum and procephalic lobe, advancing from caudal to rostral and from lateral to medial. multicellular structure